i've used different nutrients to try and fix the problem. I'm really confused here. I always get into about 3 weeks of flower and little light spots start forming on older leaves usually around the center of the light. The spots turn into crispy pieces and brown spots appear. I've tried Calmag one cycle, didn't work. I tried pk booster thinking it was a Potassium deficiency, didn't work. Right now I was using Mbferts.com nutrient line but saw some problems so I switched to lucas formula since I had a full bottle of Floranova bloom laying around. I started with full strength 8ml a gallon and I watched ph drop daily and ppm went up. So I back off to around 500 ppms and everything started turning around. ppms drop, ph was slowly rising and I thought all was good.
I then started seeing a little light spots so I upped the nutrients to 630ppms. Nothing was changing and the light spots were moving to different leaves (always older) so I added 2.5ml per gallon of epsom salts thinking it was a magnesium deficiency and the ppms rose to 680. a day goes by and now the ppm is over 700 and the plants drank a good amount of water. So now I added ro water to drop the ppm down to 600. And last but not least I added some silica at half the recommended strength 0-0-4 for a little extra potash just incase.
I then started seeing a little light spots so I upped the nutrients to 630ppms. Nothing was changing and the light spots were moving to different leaves (always older) so I added 2.5ml per gallon of epsom salts thinking it was a magnesium deficiency and the ppms rose to 680. a day goes by and now the ppm is over 700 and the plants drank a good amount of water. So now I added ro water to drop the ppm down to 600. And last but not least I added some silica at half the recommended strength 0-0-4 for a little extra potash just incase.